SnO2纳米颗粒对Sn0.6Cu钎料微观组织及界面金属间化合物的影响

Effects of SnO2 nanoparticles on microstructure and intermetallic compounds of Sn0.6Cu solder

摘要:

本文利用超声波辅助法制备了SnO2纳米颗粒增强Sn0.6Cu钎料。研究了SnO2对钎料的微观组织、熔化性能的影响，以及Cu/Sn0.6Cu-XSnO2/Cu钎焊接头界面反应产物的变化，测量了金属间化合物层的厚度和晶粒尺寸。结果表明：1.0wt.% SnO2很好的抑制了钎料中β-Sn的长大，细化了晶粒尺寸；含SnO2钎料的熔点与不含SnO2钎料熔点基本相同，但熔程明显减小；钎料熔炼过程中施加超声波可以细化晶粒，制得的钎料熔点和液相线温度也低于普通熔炼钎料。用含SnO2钎料钎焊接头界面处的IMC层更薄且晶粒尺寸更小，主要是因为SnO2纳米颗粒吸附在界面金属间化合物的晶面处阻碍铜板与钎料基体之间的相互扩散，导致IMC的形成驱动力较低，从而抑制了界面化合物的生长。

Abstract:

In this study, a lead-free composite solder was synthesized by adding SnO2 nanoparticles in Sn0.6Cu solder by ultrasonic-assisted method. Effects of the SnO2 nanoparticles on the microstructure, melting property, and the interfacial reaction products of Cu/Sn0.6Cu-XSnO2/Cu brazing joints were investigated. The thickness and grain size of intermetallic compound layer were measured. The results showed that 1.0wt.% SnO2 inhibited the growth of β-Sn in the brazing filler metal and refined the grain size. The melting point of the SnO2-containing solder is substantially the same as that of the SnO2-free solder, but the melting range is significantly reduced. In addition, The application of ultrasonic waves during the solders melting process can refine the grains, the melting point and liquidus temperature of the solder are also lower than the conventional melting solder. the IMC layer at the interface of the solder joint with SnO2 solder is thinner and the grain size is smaller. The main reason is that SnO2 nanoparticles are adsorbed to the crystal plane of the interfacial intermetallic compound, which hinders the interdiffusion between the copper plate and the solder matrix, resulting in a lower driving force for the formation of IMC, thus hindering the growth of interface compound.